Open AccessMammalian cells contain a second nucleocytoplasmic hexosaminidase
Author(s) -
Martin Gutternigg,
Dubravko Rendić,
Regina Voglauer,
Thomas Iskratsch,
Iain B. H. Wilson
Publication year - 2009
Publication title -
biochemical journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.706
H-Index - 265
eISSN - 1470-8728
pISSN - 0264-6021
DOI - 10.1042/bj20081630
Subject(s) - hexosaminidase , cleave , cytosol , biology , recombinant dna , biochemistry , cytoplasm , gene , enzyme , microbiology and biotechnology
Some thirty years ago, work on mammalian tissues suggested the presence of two cytosolic hexosaminidases in mammalian cells; one of these has been more recently characterized in a recombinant form and has an important role in cellular function due to its ability to cleave beta-N-acetylglucosamine residues from a variety of nuclear and cytoplasmic proteins. However, the molecular nature of the second cytosolic hexosaminidase, named hexosaminidase D, has remained obscure. In the present study, we molecularly characterize for the first time the human and murine recombinant forms of enzymes, encoded by HEXDC genes, which appear to correspond to hexosaminidase D in terms of substrate specificity, pH dependency and temperature stability. Furthermore, a Myc-tagged form of this novel hexosaminidase displays a nucleocytoplasmic localization. Transcripts of the corresponding gene are expressed in a number of murine tissues. On the basis of its sequence, this enzyme represents, along with the lysosomal hexosaminidase subunits encoded by the HEXA and HEXB genes, the third class 20 glycosidase to be identified from mammalian sources.